Towards chiral non-racemic cis -1,3-disubstituted cyclopentane 1,4-diphosphines
摘要:
Reaction of dialkyl- or diaryl-trans-(3,4-epoxycyclopentyl)phosphine oxides 2 with the lithium derivative of methyldiphenylphosphine oxide gives a mixture of (+/-)-t-4- and (+/-)-c-4-(disubstituted phosphinoyl)-t-2-(diphenylphosphinoyl-methyl)-r-1-cyclopentanol derivatives 13a-c and 16a-c, which could be obtained in pure form by separation of the corresponding acetates 14a-c and 17a-c followed by methanolysis. Compounds 13b and 16b were transformed into the corresponding dehydroxy derivatives 19 and 21 through the Barton procedure. Additionally, 16a was transformed into a diastereomeric mixture of carbamates 22 and 23 on reaction with (S)-alpha-phenylethylisocyanate which could be separated by repeated crystallization. The relative configuration of compounds 13b, 17a, 21 and 22 was established by X-ray diffraction analysis. (C) 2002 Elsevier Science Ltd. All rights reserved.
Towards chiral non-racemic cis -1,3-disubstituted cyclopentane 1,4-diphosphines
摘要:
Reaction of dialkyl- or diaryl-trans-(3,4-epoxycyclopentyl)phosphine oxides 2 with the lithium derivative of methyldiphenylphosphine oxide gives a mixture of (+/-)-t-4- and (+/-)-c-4-(disubstituted phosphinoyl)-t-2-(diphenylphosphinoyl-methyl)-r-1-cyclopentanol derivatives 13a-c and 16a-c, which could be obtained in pure form by separation of the corresponding acetates 14a-c and 17a-c followed by methanolysis. Compounds 13b and 16b were transformed into the corresponding dehydroxy derivatives 19 and 21 through the Barton procedure. Additionally, 16a was transformed into a diastereomeric mixture of carbamates 22 and 23 on reaction with (S)-alpha-phenylethylisocyanate which could be separated by repeated crystallization. The relative configuration of compounds 13b, 17a, 21 and 22 was established by X-ray diffraction analysis. (C) 2002 Elsevier Science Ltd. All rights reserved.
Reaction of dialkyl- or diaryl-trans-(3,4-epoxycyclopentyl)phosphine oxides 2 with the lithium derivative of methyldiphenylphosphine oxide gives a mixture of (+/-)-t-4- and (+/-)-c-4-(disubstituted phosphinoyl)-t-2-(diphenylphosphinoyl-methyl)-r-1-cyclopentanol derivatives 13a-c and 16a-c, which could be obtained in pure form by separation of the corresponding acetates 14a-c and 17a-c followed by methanolysis. Compounds 13b and 16b were transformed into the corresponding dehydroxy derivatives 19 and 21 through the Barton procedure. Additionally, 16a was transformed into a diastereomeric mixture of carbamates 22 and 23 on reaction with (S)-alpha-phenylethylisocyanate which could be separated by repeated crystallization. The relative configuration of compounds 13b, 17a, 21 and 22 was established by X-ray diffraction analysis. (C) 2002 Elsevier Science Ltd. All rights reserved.